Effect of microencapsulation with calcium alginate and resistant maize starch on survival of Lactobacillus casei and sensory properties of cream-filled cake

Investigations have shown benefits effects of probiotics. The purpose of this study was to develop a microencapsulated probioticproduct based on cream-filled cake and determine its sensory charactersitics and acceptability by consumers. Lactobacillus casei PTCC 1608 was encapsulated with calcium alginate and resistant maize starch beads and used to prepare a cream-filled cake. A control cake sample was prepared using ordinary، freeLactobacillus casei PTCC 1608. Bacterial survival، pH and sensory characteristics of the experiomental and control cake samples were compared during 40 days of storage at 4oCand 25oC. In addition، acidification kinetics in the 2 samples، over a period of 48 hours، after inoculation in an MRS broth (de Man-Rogasa-Sharpe(was dtermined. The size and shape of the microcapsules were determined by optical microscopy. pH changes in the microencapsulated cake were less during storage. Furthermore، in the encapsulated cake the amount of acid produced was lower than that of the free culture. Survival of the bacteria was hihgher in the cake sample prepared with encapsulated bacteria due to protection of cells by microencapsulation. Survival of the probiotics was better at the lower temperature (4 oC). Finally، addition of probiotic cultures، whether in the free or encapsulated state، did not significantly affect texture، colour، flavour or after-taste of the product during storage (p>0. 05). The free and encapsulated probiotic bacteria do not substantially alter the overall sensory characteristics of a cream-filled cake. However، microencapsulation helps to enhance the survival of probiotic bacteria in the product during storage.